By Jeffrey Laurence, M.D.

November 16, 2007—Antiretroviral therapy can be as effective in resource-poor countries as in richer nations—if people take their medications. The vast majority of patients who change or stop treatment do so because of drug side effects, not drug failure, a point emphasized by the work of amfAR's TREAT Asia HIV Observational Database (TAHOD). A TAHOD report published in the October 2007 issue of HIV Medicine suggests that one particular side effect, anemia, can have a significant impact on both adherence and quality of life, and should therefore be taken into consideration when choosing an antiretroviral (ARV) regimen.

TREAT Asia researchers have been studying the effects of the two most widely used combinations of ARVs in Asia—those involving either AZT or d4T (stavudine)—in patients who later stopped their therapy. These medications are common because they are relatively low-cost generic drugs and come in convenient fixed-dose forms. But each drug also has certain side effects. Knowing how well these drugs are tolerated in everyday patient care is essential to predicting the success of large-scale treatment programs.

According to the HIV Medicine study, those who started on a regimen containing AZT were much more likely to stop within the first nine months of treatment, compared with those who began on d4T. Anemia, a major side effect of AZT, occurred in 13 percent of the patients taking the drug. But researchers discovered that having been on a previous ARV regimen appeared to substantially lower the risk of developing anemia on AZT by about two-thirds.

The practical implications of this study suggest that health-care providers should run a simple blood test at the start of drug therapy to rule out anemia, and they should avoid AZT if anemia is present. If the side effects of d4T prove intolerable (d4T can cause potentially serious metabolic and nervous system complications), the study supports switching to AZT, at least in the short term, because the protective effect of prior ARV use can keep the patient safe from anemia.

Results from amfAR's TREAT Asia Initiative and other surveys show that limitations in infrastructure and access to sophisticated lab testing do not necessarily impede use of potent anti-HIV drugs. TAHOD-based studies are providing guidance on how to use available resources to offer the best possible care to people with HIV/AIDS.